Over the last few years there has been a very substantial demand for portable electric heaters which can be moved from room to room in a house or building. Some of these heaters operate using radiant or convection heating techniques. In addition there are many newly designed portable heaters which operate using a fan heater and these fan type heaters have been particularly well suited for the most up to date molding techniques which has resulted in even more compact constructions adding to the portability of the fan heater.
One noticeable drawback resulting from the most recent fan heater constructions as described immediately above is that they are very localized in terms of direction of air flow from the heater, i.e. the hot air is blown in one direction only and because the heaters themselves are quite small this limits the area covered by the heater.
I have earlier developed an oscillating louver arrangement for use in a fan construction as covered in Canadian patent No. 1,130,251 issued Aug. 24, 1982 and it's counterpart corresponding U.S. Pat. No. 4,437,394 issued Mar. 20, 1984. The specific modular construction from my earlier fan is also covered by Canadian patent No. 1,169,828 issued June 26, 1984. The concept of movable louvers which are described in the above noted patents would provide substantially increased heat coverage when used in combination with a heater fan. However, it is important that the gearing used to drive the louver blades should not be affected by heat buildup within the heater fan particularly in view of the potential of using lightweight plastic in the construction of this gearing. Such lightweight plastics are very important from a commercial standpoint in that they can be produced on a mass basis using standard molding techniques at a very low cost. From a use standpoint, the lightweight plastic components are extremely beneficial in that they present almost no load which would otherwise adversely effect the fan aspect of the heater. However, from a negative standpoint there are problems associated with using lightweight plastic in close proximity to the heating element of a fan heater because of the potential of heat related damage to the plastic.
For example, there have recently been a few attempts to construct plastic oscillating fan heaters. However, prior to my invention, these attempts have required side to side movement of the entire heater housing mounted atop a separate motor and drive system control outside of that housing. Therefore, two motors are used, one for the fan blade and heater operation and the other for oscillating the housing containing the fan blade and heater. Again, this has been expensive and complicated because of the inability to prevent heat damage to the plastic drive components which when located directly within the housing with the heater are otherwise useable to operate a louver system rather than having to oscillate the entire housing.